A Universal SFDM Halo Mass for the Andromeda and Milky Way's dSphs?

TL;DR

This study investigates scalar field dark matter models for dwarf spheroidal galaxies, finding that low mass-to-light ratio galaxies align better with SFDM, while high ratio galaxies fit NFW profiles, supporting alternative dark matter theories.

Contribution

The paper provides a comparative analysis of SFDM and NFW profiles in dwarf spheroidals, highlighting the conditions under which each model is more appropriate.

Findings

Low mass-to-light ratio dwarfs favor SFDM models.

High mass-to-light ratio dwarfs are better described by NFW profiles.

Results support using dwarf galaxy dynamics to test dark matter models.

Abstract

Dwarf spheroidal galaxies are the most common type of galaxies, and are the most dark matter dominated objects in the Universe. Therefore, they are ideal laboratories to test any dark matter model. The Bose-Einstein condensate/scalar field dark matter model considers that the dark matter is composed by spinless-ultra-light particles which can be described by a scalar field. This model is an alternative to the $\Lambda$-cold dark matter model. In this work I study the kinematics of the dwarf spheroidal satellite galaxies of the Milky Way and Andromeda, under the scalar field/BEC dark matter paradigm in two limits: when the self interacting parameter is equal to zero, and when the self interacting parameter is $\gg1$. I find that dwarf spheroidal galaxies with very high mass-to-light ratios (higher than $100$) are in better agreement with an NFW mass density profile. On the other hand, dwarf spheroidal galaxies with relatively low mass-to-light ratios and high luminosities are better described with the SFDM model. Such results are very encouraging to further test alternative dark matter models using the dynamics of dwarf galaxies as a tool.